Disposable lid having polymer composite of polyolefin and mineral filler

ABSTRACT

Disposable lid comprises a thermoformed sheet in the shape of a lid for a hot beverage container. The sheet comprises a polymer composite of a polyolefin and at least one mineral filler. The sheet has a thickness less than about 0.035 inches and a heat deflection temperature at least comparable to that of high impact polystyrene.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims the benefit of and priority to U.S. ProvisionalApplication Ser. No. 61/477,886, filed Apr. 21, 2011, which is herebyincorporated by reference in its entirety.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present application generally relates to polymer compositionsparticularly suited for disposable lids and the like. Particularly, thepresent application relates to a disposable lid comprising athermoformed sheet having a polymer composite of polyolefin and at leastone mineral filler.

2. Description of Related Art

Hot beverages, such as freshly brewed coffee for people on the go, areusually served in heavy paper cups with disposable lids. Coffee istypically brewed at 90-96° C., held at 82-88° C. and served at 70-80° C.A coffee cup lid preferably has a mechanical strength to withstand theforce required to push the lid onto the cup and to maintain thedimensional stability at the temperature of the coffee. The mechanicalstrength of a material within a range of temperatures can be correlatedto the material's heat deflection temperature (“HDT”) or deflectiontemperature under load (“DTUL”). Current lidding material for hotbeverage cups is primarily made of high impact polystyrene (“HIPS”),which has an ease of processing and a good balance between rigidity andtoughness due to its amorphous structure. However, high impactpolystyrene resin can be susceptible to chemical attack and solventcrazing. In addition, the presence of residual styrene monomer in theresin can cause an unpleasant odor. Furthermore, high impact polystyreneresin, amongst all the commodity resins, has a comparatively high carbonfootprint. Therefore, there remains an opportunity for an improveddisposable lid.

SUMMARY OF THE INVENTION

The purpose and advantages of the present application will be set forthin and apparent from the description that follows, as well as will belearned by practice of the application. Additional advantages of theapplication will be realized and attained by the apparatus particularlypointed out in the written description and claims hereof, as well asfrom the appended drawings.

To achieve these and other advantages and in accordance with the purposeof the application, as embodied and broadly described, the applicationincludes a disposable lid comprising a thermoformed sheet in the shapeof a lid for a hot beverage container. The sheet comprises a polymercomposite of a polyolefin and at least one mineral filler. The sheet hasa thickness less than about 0.035 inches and a heat deflectiontemperature at least comparable to that of high impact polystyrene.

In accordance with one aspect, the heat deflection temperature can be atleast about that of high impact polystyrene. Particularly, the heatdeflection temperature according to ASTM D648-06 Standard Test Methodfor Deflection Temperature of Plastics Under Flexural Load in theEdgewise Position (2006) can be at least about 87° C.

As embodied herein, the mineral filler can include a high aspect ratiomineral filler, for example, selected from the group consisting of talc,mica, wollastonite, or combinations thereof. For example, the polymercomposite can comprise at least about 10% by weight of the high aspectratio mineral filler. Additionally or alternatively, the mineral fillercan include a low aspect ratio mineral filler, such as calciumcarbonate. For example, the polymer composite can comprise at leastabout 20% by weight of the low aspect ratio mineral filler. Thepolyolefin can be selected from the group consisting of polypropylenehomopolymer, polypropylene impact copolymer, ethylene-propylene randomcopolymer, high density polyethylene, or combinations thereof.

In one embodiment, the polyolefin includes polypropylene, the mineralfiller includes a high aspect ratio mineral filler, and the polymercomposite comprises at least about 10% by weight of the mineral filler.In another embodiment, the polyolefin includes polypropylene, themineral filler includes a low aspect ratio mineral filler, and thepolymer composite comprises at least about 20% by weight of the mineralfiller. In yet another embodiment, the polyolefin includes high densitypolyethylene, the mineral filler includes a high aspect ratio mineralfiller, and the polymer composite comprises at least about 20% by weightof the mineral filler. In yet another embodiment, the polyolefinincludes high density polyethylene, the mineral filler includes a lowaspect ratio mineral filler, and the polymer composite comprises atleast about 40% by weight of the mineral filler.

In accordance with another aspect, the polyolefin can includepolypropylene, the mineral filler can include a high aspect ratiomineral filler, and the polymer composite can have a shrinkagecomparable to that of high impact polystyrene. For example, the polymercomposite can have a shrinkage of about 0.5% to about 1.0% when measuredaccording to the ASTM D955 standard (1996). In this manner, the polymercomposite comprises about 20% to about 40% by weight of the mineralfiller.

In accordance with another aspect, the polyolefin can includepolyethylene, the mineral filler can include a high aspect ratio mineralfiller, and the polymer composite can have a shrinkage comparable tothat of polypropylene. As such, the polymer composite can have ashrinkage of about 1.25% to about 1.75% when measured according to theASTM D955 standard (1996). In this embodiment, the polymer compositecomprises about 30% to about 50% by weight of the mineral filler.

In accordance with one aspect of the disclosed subject matter, thepolymer composite consists essentially of the polyolefin and the atleast one mineral filler. However, the polymer composite can furthercomprise additives selected from the group consisting of colorants,processing aids, and combinations thereof.

As embodied herein, the hot beverage container can be a coffee cup,although a lid for other suitable containers is contemplated.

In accordance with another aspect, the polymer composite can have acarbon footprint lower than high impact polystyrene. For example, thepolymer composite can have a greenhouse gas emission lower than highimpact polystyrene.

It is to be understood that both the foregoing general description andthe following detailed description are exemplary and are intended toprovide further explanation of the application claimed.

The accompanying drawings, which are incorporated in and constitute partof this specification, are included to illustrate and provide a furtherunderstanding of the apparatus of the application. Together with thewritten description, the drawings serve to explain the principles of theapplication.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a graph of the heat deflection temperature of neat high impactpolystyrene, neat polypropylene, neat high density polyethylene, andcertain mineral filled polymer composites, respectively, in accordancewith the disclosed subject matter.

FIG. 2 is a graph of the shrinkage characteristics of neat high impactpolystyrene, neat polypropylene, neat high density polyethylene, andcertain mineral filled polymer composites, respectively, in accordancewith the disclosed subject matter.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

Reference will now be made in detail to the present preferredembodiments of the application, examples of which are illustrated in theaccompanying drawings. The disposable lids presented herein generallyare intended for use with cups or other containers for holding hightemperature beverages, such as coffee. Although reference will be madeherein to lids for hot beverage cups, other similar or suitable uses arecontemplated.

Typically, polyolefins have a heat deflection temperature lower thanhigh impact polystyrene (“HIPS”) and thus are not suitable for use alone(i.e., neat) as a lidding material for hot beverage cups. However, inaccordance with the disclosed subject matter, the heat deflectiontemperature of the polyolefin can be improved by adding at least onemineral filler to form a polymer composite. The resulting polymercomposite can have a heat deflection temperature at least about that ofhigh impact polystyrene and thus be suitable for use as a liddingmaterial for hot beverage cups or the like.

Disposable lids in accordance with the disclosed subject matter includea thermoformed sheet in the shape of a lid for a hot beverage container.The sheet comprises a polymer composite of a polyolefin and at least onemineral filler. The sheet has a thickness less than about 0.035 inchesand a heat deflection temperature at least comparable to that of highimpact polystyrene.

In one embodiment, the mineral filler can include any suitable mineralfiller for increasing the heat deflection temperature of the polyolefin.For example but without limitation, the mineral filler can include ahigh aspect ratio filler, a low aspect ratio filler, or a blend of both.The term “aspect ratio” of a particle is defined herein for purpose ofunderstanding as a ratio of a largest dimension of the particle dividedby a smallest dimension of the particle. The aspect ratios aredetermined by scanning under an electron microscope (2,000 timesmagnified) and visually viewing the outside surfaces of the particles todetermine the lengths and thicknesses of the particles.

A high aspect ratio filler is defined herein as a filler having anaspect ratio of at least about 5:1. The high aspect ratio fillers of thepresent disclosed subject matter generally have an aspect of from about5:1 to about 40:1, and preferably from about 10:1 to about 20:1. Thehigh aspect filler can include talc, mica, wollastonite, or combinationsthereof. Commercially available talc materials include, but are notlimited to, JETFIL® 575, available from Luzenac America of Englewood,Colo. Commercially available mica materials include SUZOREX® 325-PP,available from Zemex Industrial Minerals, Inc. Commercially availablewollastonite includes, but is not limited to, the NYGLOS® series ofwollastonite, available from NYCO Minerals Inc. of Calgary, Alberta,Canada.

A low aspect ratio filler of the disclosed subject matter generally hasan aspect ratio of from 1:1 to about 3:1, preferably from 1:1 to about2:1. The low aspect ratio filler can include calcium carbonate, bariumsulfate, or the combination thereof. Commercially available calciumcarbonate includes, but is not limited to, OMYACARB FT®, available fromOMYA Inc. of Cincinnati, Ohio, or Supercoat®, from Imerys PerformanceMinerals Inc. of Alpharetta, Ga. One example of commercially availablebarium sulfate is BARITE 2075®, available from Polar Minerals in Mentor,Ohio.

When the at least one filler comprises a blend of high and low aspectratio fillers, the filler mixture can include any suitable weightpercentage of the high and low aspect ratio fillers. For example, thefiller mixture can comprise at least 50 wt. % high aspect ratio filler.In one embodiment, the filler mixture can be from about 50 to about 80wt. % high aspect ratio filler and from about 20 to about 50 wt. % lowaspect ratio filler.

In accordance with one aspect, the polyolefin can be any suitablepolyolefin. For example but without limitation, the polyolefin can beselected from the group consisting of polypropylene homopolymer,polypropylene impact copolymer, ethylene-propylene random copolymer,high density polyethylene, or combinations thereof. The polyolefin canbe a blend of homopolymer polypropylene and impact copolymerpolypropylene, in any desired weight percent, such as a 60/40 blend, ora blend ratio sufficient o achieve a desirable impact property of thecomposite.

In accordance with one aspect, the polymer composite can consistessentially of the polyolefin and the at least one mineral filler.However, the polymer composite can further comprise any additives knownto one of ordinary skill in the art. For example, but withoutlimitation, the additive can include colorants, processing aids such asthose commonly used for processing composites, or combination thereof.

In accordance with one aspect, the disposable lid can be formed using avariety of conventional manufacturing and forming processes, includingthermoforming or injecting molding processes, although a thermoformingprocess is employed herein. According to one method of manufacturing,pellets of a polyolefin resin are melted in a twin screw extruder.Powders of the at least one mineral filler are mixed with and/or addedinto the polyolefin melt to form a blend. The blend is extruded througha die to form an extruded sheet. The extruded sheet is then thermoformedto a desired shape of the disposable lid. Alternatively, amineral-filled compound of high filler content in pellet form can beproduced from a typical compounding process, and the pellets furtherdiluted to a desirable filler content in the sheet extrusion process.

The thickness of the lid can be selected as desired, but is typicallyless than about 0.15 inches, preferably less than about 0.035 inches.Preferably, the lid can be about 0.01 to about 0.025 inches thick. Thelid can be the natural color of the polyolefin/filler mixture, or avariety of colors or color combinations. The height, weight, shape, anddesign of the lid can be selected as desired to fit a suitable hotbeverage container, such as a coffee cup, as is well known in the art.For example, the lid can weigh about 3 to about 4 grams. Exemplary liddesigns include, but are not limited to, those described and shown inU.S. Pat. Nos. 7,819,271, 7,789,260, 7,691,302, D556,573, D544,793,D541,651 D541,650, D541,153, D540,675, D540,674, D540,673, D540,672,D540,166, D540,165, D539,646, D533,778, D635,855, 7,731,047, 7,513,382,7,246,715, D540,167, D539,650, D539,649, D536,249, D535,561, 7,159,732,7,156,251, 7,134,566, 7,131,551, D530,602, 7,063,224, D514,445,D514,444, 6,874,649, 6,732,875, D489,260, D485,758, 6,679,397,6,644,490, D478,006, D477,223, D476,891, D476,566, 4,753,365, D287,919,4,615,459, and 4,589,569, the contents of each of which is incorporatedherein by reference in its entirety.

In accordance with one aspect of the disclosed subject matter, the heatdeflection temperature (“HDT”) also known as the deflection temperatureunder load (“DTUL”) can be determined according to ASTM D648-06,Standard Test method for Deflection Temperature of Plastics UnderFlexural Load in the Edgewise Position (2006). For the purpose ofillustration and not limitation, Table 1 includes the heat deflectiontemperature measured according to the ASTM D648-06 standard (2006) forneat high impact polystyrene, neat polypropylene (“PP”), neat highdensity polyethylene (“HDPE”), and various mineral filled polymercomposites in accordance with the disclosed subject matter. The dataprovided in Table 1 is based on nominally 12.7 mm wide by 3.17 mm thickinjection molded bars with a span of 101.6 mm. A load of 2.5N wasapplied to achieve a fiber stress of 0.455 MPa (66 PSI). The temperatureof the heat-transfer medium was ramped at 2.0° C./min. The deflectionwas reset to zero at 30° C. to allow for any low temperature creep. Thetemperature at which the sample deflected an additional 0.25 mm wasconsidered the heat deflection temperature. For the purpose ofillustration and not limitation, FIG. 1 provides a graphicalrepresentation of the heat deflection temperature data provided inTable 1. Particularly, FIG. 1 shows the increase of heat deflectiontemperature as a function of mineral filler content for four differentcombinations of polypropylene or high density polyethylene with talc orcalcium carbonate, respectively, as compared with neat HIPS as acontrol.

TABLE 1 DTUL and IM Mold Shrinkage of HIPS, PP, HDPE and Mineral-filledcomposites Filler IM mold Matrix Filler (wt DTUL⁶ shrinkage ExamplePolymer Type %) (° C.) (%) Comparative Example 1 HIPS¹ None 0 87 0.74%Comparative Example 2 HDPE² None 0 69 2.60% Comparative Example 3 PP³None 0 80 1.53% Comparative Example 4 PP⁴ None 0 79 1.46% ComparativeExample 5 PP⁵ None 0 100 1.23% Inventive Example 01 HDPE² Talc 11 792.33% Inventive Example 02 HDPE² Talc 20 90 2.02% Inventive Example 03HDPE² Talc 30 96 1.61% Inventive Example 04 HDPE² Talc 40 108 1.53%Inventive Example 05 HDPE² Talc 50 115 1.29% Inventive Example 06 HDPE²CaCO₃ 10 68 2.82% Inventive Example 07 HDPE² CaCO₃ 20 72 2.38% InventiveExample 08 HDPE² CaCO₃ 30 79 2.29% Inventive Example 09 HDPE² CaCO₃ 4084 2.06% Inventive Example 10 HDPE² CaCO₃ 50 92 1.76% Inventive Example11 HDPE² CaCO₃ 60 100 Inventive Example 12 PP³ Talc 10 105 0.94%Inventive Example 13 PP³ Talc 20 115 0.83% Inventive Example 14 PP³ Talc30 123 0.69% Inventive Example 15 PP³ Talc 40 130 0.60% InventiveExample 16 PP³ CaCO₃ 10 84 1.37% Inventive Example 17 PP³ CaCO₃ 20 891.29% Inventive Example 18 PP³ CaCO₃ 30 93 1.24% Inventive Example 19PP³ CaCO₃ 40 97 1.06% Inventive Example 20 PP³ CaCO₃ 50 101 0.94% ¹HighImpact Polystyrene, Total Petrochemicals 940E ²High DensityPolyethylene, Density = 0.963 g/cc ³PP Homopolymer PP/Impact Copolymerblend. Blend ratio 60/40 ⁴PP Impact Copolymer ⁵PP Homopolymer⁶DTUL—Deflection Temperature Under Load (66 psi) per ASTM D648.

As can be seen in the data of Table 1 and FIG. 1, neat high impactpolystyrene, with a heat deflection temperature of 87° C., falls inbetween the range of temperature where coffee is brewed and served. Theheat deflection temperature of polypropylene copolymer or polypropylenehomopolymer/copolymer blend, at about 79-80° C., is lower than thatprovided by neat high impact polystyrene. The heat deflectiontemperature for neat high density polyethylene, at about 69° C.,however, is shown to be outside the range of temperature where a lidmade from neat high density polyethylene would perform satisfactorily.

Examples 1-20 in accordance with the disclosed subject matter of Table 1show the heat deflection temperatures of various polyolefin and mineralfiller combinations at different levels of mineral filler. Of thedifferent polyolefin and mineral filler combinations, the calciumcarbonate filled polyolefins have a gradual increase in heat deflectiontemperature relative a respective non-filled (i.e. neat) polyolefin asthe mineral content is increased. By contrast, the talc filledpolyolefins have a much higher increase in heat deflection temperatureas the mineral filler content is increased. Unexpectedly, the talcfilled polypropylene has a more significant increase in heat deflectiontemperature, even with the talc content as low as about 10%.

As shown in the data of Table 1 and FIG. 1, a polymer composite inaccordance with the disclosed subject matter therefore can be providedwith a heat deflection temperature comparable to, equal to, or greaterthan high impact polystyrene. For example, to achieve equal or greaterheat deflection temperature than high impact polystyrene, if the mineralfiller includes a high aspect ratio mineral (e.g. talc), the polymercomposite can comprise as little as about 10% by weight of the mineralfiller (see Example 12). Indeed, as shown in FIG. 1, when polypropyleneis used, even less than 10% by weight of talc is needed to achieve thesame heat deflection temperature as high impact polystyrene. Bycontrast, if the mineral filler includes a low aspect mineral filler(e.g. calcium carbonate), the polymer composite can comprise at leastabout 20% by weight of the mineral filler (see Example 17) to achievethe equal or greater heat deflection temperature than high impactpolystyrene.

As shown by Example 2, when the polyolefin includes high densitypolyethylene, the mineral filler includes a high aspect ratio mineralfiller (e.g. talc), and the polymer composite comprises at least about20% by weight of the mineral filler, the heat deflection temperaturewill be greater than that of high impact polystyrene. As shown byExample 10, when the polyolefin includes high density polyethylene, themineral filler includes a low aspect ratio mineral filler (e.g. calciumcarbonate), and the polymer composite comprises at least about 50% byweight of the mineral filler, the heat deflection temperature will begreater than that of high impact polystyrene. As shown by Example 12,when the polyolefin includes polypropylene, the mineral filler includesa high aspect ratio mineral filler (e.g. talc), and the polymercomposite comprises at least about 10% by weight of the mineral filler,the heat deflection temperature will be greater than that of high impactpolystyrene. As shown by Example 17, when the polyolefin includespolypropylene, the mineral filler includes a low aspect ratio mineralfiller (e.g. calcium carbonate), and the polymer composite comprises atleast about 20% by weight of the mineral filler, the heat deflectiontemperature will be greater than that of high impact polystyrene.

For the purpose of illustration and not limitation, Table 1 and FIG. 2shows the shrinkage characteristics of polypropylene, high densitypolyethylene, high impact polystyrene and mineral filled polypropyleneand mineral filled high density polyethylene. The shrinkage can bemeasured in accordance with the ASTM D955 (1996) standard usinginjection molded bars of the dimensions 12.7 min×3.2 mm×127 mm inaccordance with the standard and as well known in the art. Mineralfilled polypropylene can overcome disadvantages of polypropylene (neat)in the mismatch in shrinkage as compared to high impact polystyrene,therefore allowing the use of existing high impact polystyrene toolingfor making a part with similar shrinkage of between about 0.5% and about1.0%. For example, as shown in FIG. 2, talc filled polypropylene at20-40% talc is suitable for replacing high impact polystyrene fromshrinkage perspective. Similarly, mineral filled high densitypolyethylene can overcome the disadvantage of high density polyethylenein the mismatch in shrinkage as compared to polypropylene, thereforeallowing the use of existing polypropylene tooling for making a mineralfilled high density polyethylene part with similar shrinkage topolypropylene of about 1.25% to about 1.75%. For example, as shown inFIG. 2, talc filled high density polyethylene at 30-50% talc is suitablefor replacing neat polypropylene from shrinkage perspective.

In accordance with another aspect, the polymer composite can have acarbon footprint lower than high impact polystyrene. For example, thepolymer composite can have a greenhouse gas emission lower than highimpact polystyrene. For the purpose of illustration and not limitation,Table 2 shows cradle-to-grave greenhouse gases emissions of lids inaccordance with the disclosed subject matter as compared to lids of highimpact polystyrene. The two lids have similar rigidity and performsimilarly as a hot beverage cup lid. The comparative example was madefrom high impact polystyrene sheet of about 0.0214 inches thick andweighed about 3.83 grams. The example in accordance with the disclosedsubject matter include 40% talc-filled polypropylene and was made from a0.0167 inches thick sheet and weighed about 3.32 grams. A base unit of10,000 pieces was used to calculate the greenhouse gases emissions.Several factors contributed to the much lower greenhouse gases emissionof the example in accordance with the disclosed subject matter. Thesefactors include polymer density, GHG emission of base polymers andminerals, and the amount of minerals incorporated in the composite. Ascan be seen in FIG. 2, the talc filled polypropylene lid has a nearly50% reduction in greenhouse gases emission as compared to a similarlyperforming lid made of high impact polystyrene.

TABLE 2 Greenhouse Gases Emissions of a typical hot cup lid Weight ofunit polymer GHG GHG Part weight Parts weight per unit (Kg CO₂ (Kg CO₂(grams) per unit (Kg) (Kg) eq./Kg matl.) eq.) HIPS lids 3.83 10,000 38.338.3 4.68 81.5 40% Talc-filled 3.32 10,000 33.2 19.3 2.88 43.5 PP lids %Reduction 50% 47%

While the present application is described herein in terms of certainpreferred embodiments, those skilled in the art will recognize thatvarious modifications and improvements can be made to the applicationwithout departing from the scope thereof. For example, which the presentapplication describes a disposable lid for a hot beverage container suchas a coffee cup, the polymer composites in accordance with theapplication could be used in applications other than lidding where theimproved heat deflection temperature of a mineral filled polymer isdesired. Thus, it is intended that the present application includemodifications and variations that are within the scope of the appendedclaims and their equivalents. Moreover, although individual features ofone embodiment of the application are discussed herein or shown in thedrawings of one embodiment and not in other embodiments, it should beapparent that individual features of one embodiment can be combined withone or more features of another embodiment or features from a pluralityof embodiments.

In addition to the specific embodiments claimed below, the applicationis also directed to other embodiments having any other possiblecombination of the dependent features claimed below and those disclosedabove. As such, the particular features presented in the dependentclaims and disclosed above can be combined with each other in othermanners within the scope of the application such that the applicationshould be recognized as also specifically directed to other embodimentshaving any other possible combinations. Thus, the foregoing descriptionof specific embodiments of the application has been presented forpurposes of illustration and description. It is not intended to beexhaustive or to limit the application to those embodiments disclosed.

1. A disposable lid comprising: a thermoformed sheet in the shape of alid for a hot beverage container, the sheet comprising a polymercomposite of a polyolefin and at least one mineral filler; wherein thesheet has a thickness less than about 0.035 inches and a heat deflectiontemperature at least comparable to that of high impact polystyrene. 2.The disposable lid of claim 1, wherein the heat deflection temperatureis at least about that of high impact polystyrene.
 3. The disposable lidof claim 1, wherein the heat deflection temperature according to ASTMD648-06 Standard Test Method for Deflection Temperature of PlasticsUnder Flexural Load in the Edgewise Position (2006) is at least about87° C.
 4. The disposable lid of claim 1, wherein the mineral fillerincludes a high aspect ratio mineral filler.
 5. The disposable lid ofclaim 4, wherein the mineral filler is selected from the groupconsisting of talc, mica, wollastonite, or combinations thereof.
 6. Thedisposable lid of claim 4, wherein the polymer composite comprises atleast about 10% by weight of the mineral filler.
 7. The disposable lidof claim 1, wherein the mineral filler includes a low aspect ratiomineral filler.
 8. The disposable lid of claim 7, wherein the mineralfiller includes calcium carbonate.
 9. The disposable lid of claim 7,wherein the polymer composite comprises at least about 20% by weight ofthe mineral filler.
 10. The disposable lid of claim 1, wherein thepolyolefin is selected from the group consisting of polypropylenehomopolymer, polypropylene impact copolymer, ethylene-propylene randomcopolymer, high density polyethylene, or combinations thereof.
 11. Thedisposable lid of claim 1, wherein the polyolefin includespolypropylene, the mineral filler includes a high aspect ratio mineralfiller, and the polymer composite comprises at least about 10% by weightof the mineral filler.
 12. The disposable lid of claim 1, wherein thepolyolefin includes polypropylene, the mineral filler includes a lowaspect ratio mineral filler, and the polymer composite comprises atleast about 20% by weight of the mineral filler.
 13. The disposable lidof claim 1, wherein the polyolefin includes high density polyethylene,the mineral filler includes a high aspect ratio mineral filler, and thepolymer composite comprises at least about 20% by weight of the mineralfiller.
 14. The disposable lid of claim 1, wherein the polyolefinincludes high density polyethylene, the mineral filler includes a lowaspect ratio mineral filler, and the polymer composite comprises atleast about 40% by weight of the mineral filler.
 15. The disposable lidof claim 1, wherein the polyolefin includes polypropylene, the mineralfiller includes a high aspect ratio mineral filler, and the polymercomposite has a shrinkage comparable to that of high impact polystyrene.16. The disposable lid of claim 15, wherein the polymer composite has ashrinkage of about 0.5% to about 1.0% when measured according to theASTM D955 standard (1996).
 17. The disposable lid of claim 15, whereinthe polymer composite comprises about 20% to about 40% by weight of themineral filler
 18. The disposable lid of claim 1, wherein the polyolefinincludes high density polyethylene, the mineral filler includes a highaspect ratio mineral filler, and the polymer composite has a shrinkagecomparable to that of polypropylene.
 19. The disposable lid of claim 18,wherein the polymer composite has a shrinkage of about 1.25% to about1.75% when measured according to the ASTM D955 standard (1996).
 20. Thedisposable lid of claim 18, wherein the polymer composite comprisesabout 30% to about 50% by weight of the mineral filler.
 21. Thedisposable lid of claim 1, wherein the polymer composite consistsessentially of the polyolefin and the at least one mineral filler. 22.The disposable lid of claim 1, wherein the polymer composite furthercomprises additives selected from the group consisting of colorants,processing aids, and combinations thereof.
 23. The disposable lid ofclaim 1, wherein the hot beverage container is a coffee cup.
 24. Thedisposable lid of claim 1, wherein the polymer composite has a carbonfootprint lower than high impact polystyrene.
 25. The disposable lid ofclaim 1, wherein the polymer composite has a greenhouse gas emissionlower than high impact polystyrene.